Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Overview of this book

The shell remains one of the most powerful tools on a computer system — yet a large number of users are unaware of how much one can accomplish with it. Using a combination of simple commands, we will see how to solve complex problems in day to day computer usage.Linux Shell Scripting Cookbook, Second Edition will take you through useful real-world recipes designed to make your daily life easy when working with the shell. The book shows the reader how to effectively use the shell to accomplish complex tasks with ease.The book discusses basics of using the shell, general commands and proceeds to show the reader how to use them to perform complex tasks with ease.Starting with the basics of the shell, we will learn simple commands with their usages allowing us to perform operations on files of different kind. The book then proceeds to explain text processing, web interaction and concludes with backups, monitoring and other sysadmin tasks.Linux Shell Scripting Cookbook, Second Edition serves as an excellent guide to solving day to day problems using the shell and few powerful commands together to create solutions.
Table of Contents (16 chapters)
Linux Shell Scripting Cookbook
About the Authors
About the Reviewers

Finding the frequency of words used in a given file

Finding the frequency of words used in a file is an interesting exercise to apply the text-processing skills. It can be done in many different ways. Let's see how to do it.

Getting ready

We can use associative arrays, awk, sed, grep, and so on, to solve this problem in different ways. Words are alphabetic characters, delimited by space or a period. First, we should parse all the words in a given file and then the count of each word needs to be found. Words can be parsed by using regex with any of the tools, such as sed, awk, or grep.

How to do it...

We just saw the logic and ideas about the solution; now let's create the shell script as follows:

#Desc: Find out frequency of words in a file

if [ $# -ne 1 ];
  echo "Usage: $0 filename";
  exit -1


egrep -o "\b[[:alpha:]]+\b" $filename | \

awk '{ count[$0]++ }
END{ printf("%-14s%s\n","Word","Count") ;
for(ind in count)
{  printf("%-14s%d\n...